This invention relates to the art of drain cleaning apparatus and, more particularly, to an improved feed control arrangement by which a flexible snake of such apparatus can be axially advanced and retracted relative thereto during a drain cleaning operation.
It is of course well known to provide manually operable feed control devices for advancing and retracting a drain cleaning snake relative to a drain being cleaned. In some such devices, a plurality of rolls are supported in a housing, or the like, through which the snake extends, and the rolls are spaced apart about the periphery of the snake. The rolls have neutral and engaged positions relative to the snake and in which the snake, when rotated, respectively rotates in place and is axially displaced relative to the housing. In some designs, the rolls are skewed relative to the axis of the snake so as to axially displace the snake in one direction relative to the housing in response to rotation of the snake in one direction, and axial displacement of the snake in the opposite direction is achieved by reversing the direction of rotation of the snake. Examples of an arrangement of this are shown in U.S. Pat. No. 5,901,401 to Rutkowski, et al., U.S. Pat. No. 6,009,588 to Rutkowski, and U.S. Pat. No. 6,158,076 to Rutkowski, et al. In other designs, axial displacement of the snake in opposite directions relative to the housing is achieved by rotating the snake in just one direction and reversing the skew of the rolls relative thereto. Such an arrangement is shown, for example, in U.S. Pat. No. 5,031,276 to Babb, et al.
More recent feeding devices of the latter character are disclosed in U.S. Pat. No. 6,360,397 to Babb wherein the skew of the rolls is reversible by relative rotational displacement of housing members in which the rolls are supported, and in U.S. Pat. No. 6,655,228 to Margherio, et al. wherein two pairs of rolls are axially spaced apart in a housing and a third roll is mounted axially therebetween and is shiftable to selectively engage the snake against one or the other of the roll sets. All of the foregoing patents are incorporated herein by reference for background information.
The power source by which a drain cleaning snake is rotated can be a handheld, crank operated drain cleaner such as shown for example in the aforementioned U.S. Pat. No. 6,158,076 to Rutkowski, et al. a trigger actuated motor driven drain cleaner such as are shown, for example, in U.S. Pat. No. 3,224,024 to Hunt and U.S. Pat. No. 5,029,356 to Silverman, et al., or somewhat larger, ground-supported drain cleaners such as are shown for example in U.S. Pat. No. 4,580,306 to Irwin, U.S. Pat. No. 5,031,263 to Babb, et al., and U.S. Pat. No. 5,239,724 to Salecker, et al., the disclosures of which are also incorporated herein by reference for background information.
The control devices which do not require reversal of the direction of rotation of the snake in order to achieve displacement thereof in axially opposite directions are advantageous for a number of reasons. In this respect, for example, operation of the drain cleaning apparatus is made easier for the user by the latter's not having to manipulate a reversing switch for the drive motor. At the same time, however, the arrangements heretofore provided for axially displacing a snake in opposite directions without changing the direction of rotation of the snake are structurally complex and at least somewhat cumbersome to operate in requiring the user to manipulate at least one and sometimes two components to achieve reversal of the direction of the snake drive.